Volume 4, Issue 1 (March 1981)

Feasibility of Drag Bit Tunneling in Limestone

A series of experiments were performed to assess the values of performance indicators of drag bits in limestone. The experiments were done with a constant normal thrust linear cutter. The results show that for sharp drag bits, productivity and efficiency of drag bits are superior to that of disk cutters. However, the high values of cutting coefficient point to high torque requirements for drag bit machines.